RNLI Atlantic 85, Manual

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Activity 9 - Propulsion and Auxiliary Systems
B Class Atlantic 85 Manual – First Issue, June 2017
Activity 9 - Propulsion and Auxiliary Systems
Trim/tilt unit
As with previous makes of outboard motor fitted to RNLI
inshore lifeboats, the Yamaha F115 (OE 26) and F115A
(OE 33) outboard engines are fitted with an electric
trim and tilt system that is controlled by a switch on the
throttle handle. Port engine, starboard engine or both
can be selected by the trim/tilt selector switch on the
helm console.
The switch triggers, via intermediate relays in the isolation
box, one of two relays mounted on the engine, one for up
and one for down. These relays have been waterproofed
at the ILC. The relays send a current to an electric
motor that is part of the trim/tilt unit on the engine
mounting bracket.
The motor runs in two directions and operates a hydraulic
pump that moves various pistons within the unit.
The unit has a manual valve to allow the lowering of the
engine should power be lost to the unit or the unit is
defective. The handle for the valve is on the port side of the
transom plate and is turned anti-clockwise ½ to 3/4 turns
to allow a manual drop. Once the fault is rectified the
valve must be wound back in to ensure remote operation.
Should the unit fail, it will be necessary to
remove it by following the Technical Procedure:
TP-Atlantic85-50-0002. (Staff level 2)